This invention relates to holders for spools of thread and more particularly to such holders including a clutch mechanism for preventing unwanted rotation or unwinding of the spool, while enabling a withdrawal of a predetermined amount of such thread responsive to a predetermined pulling force.
The term "thread" is used herein as a generic term to designate any suitable thread, string, twine, rope or the like. It is presently thought that dental floss is the specific thread that is most likely to be stored in the holder.
Holders of the inventive type for spools of thread have many uses, one of which is to hold a relatively large supply of dental floss. The general characteristics of such a holder usually requires an almost instantaneous removal of any selected length of thread, a means for cutting and holding the cut end of thread, and a means for securing the spool to prevent it from rotating or unwinding when the thread is not being removed therefrom.
In addition, when the thread is dental floss, the entire package is capable of being as small as possible for the length of enclosed thread so that it may be carried about in a pocket or purse, with a minimum of inconvenience. Beyond this, the holder should be attractive, to present a maximum sales appeal. It should also be of a shape and size which is easy for a person to manipulate, even when such person does not have normal dexterity.
Accordingly, an object of the invention is to provide a new and improved holder and packaging system for a spool of thread. Here an object is to provide a holder which can be made almost as small as the maximum sized spool likely to be used in the holder. Further, an object is to give ready access to almost any desired length of the thread, while restraining the spool to prevent an unwanted unwinding.
Another object of the invention is to provide a basic design and form of thread holder which has general utility for virtually any size of spool or thread, and yet meets the specific needs of a dental floss holder. Here, an object is to provide a holder at a minimum cost.
In keeping with an aspect of the invention, these and other objects are accomplished by providing a housing in the form of a two part shell, made of plastic or other suitable material. One part of the housing shell includes a platform to enable a rotation of the spool with a minimum amount of friction between the spool and the shell. The other part of the housing shell includes at least one finger which depends far enough to drag, with predetermined friction, against the top of the spool. This friction is great enough to prevent an unwanted and random unwinding of the spool of thread and yet small enough to preclude any substantial opposition to a desired withdrawal of thread.